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CN108229371B - Identification method of ice-covered shape of transmission wire cross-section based on ice-shape modeling - Google Patents

Identification method of ice-covered shape of transmission wire cross-section based on ice-shape modeling Download PDF

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CN108229371B
CN108229371B CN201711470765.1A CN201711470765A CN108229371B CN 108229371 B CN108229371 B CN 108229371B CN 201711470765 A CN201711470765 A CN 201711470765A CN 108229371 B CN108229371 B CN 108229371B
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张烨
黄新波
刘新慧
张慧莹
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Xian Polytechnic University
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Abstract

The invention discloses a method for identifying the icing shape of the cross section of a power transmission conductor based on ice shape modeling, which takes digital images of the power transmission conductor before and after icing collected by two cameras as a research object, extracts the special diagnosis amount of the edge of the icing conductor through image processing methods such as image preprocessing, image segmentation, edge extraction and the like, then determines the distribution positions of four key points of the maximum thickness and the maximum diameter of the icing of the conductor on the cross section through analysis, fits the irregular icing shape of the cross section of the conductor by combining a mathematical function modeling method, and finally can further calculate the icing volume and the icing weight of the conductor within a fixed length by calculating the icing clear area of the cross section under different icing shapes, thereby quantifying the icing condition of the power transmission conductor. The method for identifying the icing shape of the cross section of the power transmission conductor based on the ice shape modeling is simple, visual and feasible in principle, and intelligently detects and identifies the icing condition of the power transmission conductor through an image processing technology and mathematical modeling knowledge.

Description

Ice-shape-modeling-based method for identifying icing shape of cross section of power transmission conductor
Technical Field
The invention belongs to the technical field of on-line monitoring of power transmission lines, and relates to a method for identifying an icing shape of a cross section of a power transmission conductor based on ice shape modeling.
Background
The transmission line is one of the most important parts of the power system, is mostly erected in the field, has wide line coverage, and is in extremely severe geographical environment and climatic conditions. The ice coating of the transmission line has great influence on the electrical and mechanical properties of the transmission line, and serious electric power accidents such as strand breakage of a lead, damage of hardware fittings and insulators, even deformation of a tower, tower falling and the like are caused by the fact that the ice coating of the transmission line easily causes ice flashover of an insulator, line tripping, large-area power failure, overload, ice coating galloping, ice shedding jumping and the like. Therefore, the problem that the atmospheric icing of the power grid is faced by the power system is solved, China is one of countries with serious icing in the world, the icing and ice melting of the power transmission line become important subjects in the field of online monitoring of the power system since the ice disaster of the power grid in the south of 2008, and accurate identification of the icing degree of the power transmission line is an important basis for guiding the ice melting of the line, so that how to effectively predict or identify and measure the icing condition of the power transmission line has very important significance for safe operation of the power grid.
At present, indirect methods are mostly adopted in engineering application to estimate the icing condition, and the lead icing thickness measurement methods adopted at home and abroad mainly comprise: measuring tool detection, ice sample weighing detection, sensor modeling detection and visual detection. With the improvement of the resolution of visible light equipment and the development of a video image processing technology, the measurement of the thickness of the ice coated on the conducting wire by combining the image processing technology and mathematical modeling becomes a hot spot in the field of online monitoring of the power transmission line. Previous measurements of wire icing thickness based on image processing were all for wire icing uniformity, i.e. wire icing shape was assumed to have a regular cross section that is approximately circular or elliptical. However, the ice coating of the conductor is mostly irregular in actual field, the cross section of the ice coated conductor is only approximate to a circle or an ellipse, certain errors are caused in the measurement of the ice coating thickness of the conductor, and the estimation of the ice melting time is influenced. The measurement of the irregular ice coating on the wire is still an open problem up to now, and the method for measuring the irregular ice coating on the wire by adopting a video image processing technology is rarely mentioned at home and abroad.
Disclosure of Invention
The invention aims to provide a method for identifying the icing shape of the cross section of a power transmission conductor based on ice shape modeling, which can calculate and identify the icing shape, the icing thickness and the icing weight of the irregular icing of the conductor more accurately and reasonably.
The technical scheme adopted by the invention is that the method for identifying the icing shape of the cross section of the power transmission conductor based on the ice shape modeling is characterized by comprising the following steps of:
step 1, installing cameras according to the positions of a wire and an iron tower, wherein one camera is installed above the wire, the other camera is installed in a position parallel to the wire, calibrating the position of the camera, and acquiring images of the wire when ice is not coated;
step 2, collecting the images of the conductor coated with ice by using the two cameras arranged in the step 1, and collecting the images of the conductor coated with ice at the positions right above and right in front of the conductor coated with ice;
step 3, respectively carrying out image preprocessing and image segmentation on the images of the ice-coated wire acquired by the two cameras in the step 2, and further extracting the edge contour of the ice-coated wire; and drawing the outer contour shape of the cross section of the lead,
step 4, obtaining l according to step 3kAnd hkCalculating the ratio alpha of the long axis to the short axis of the cross section of the ice-coated wire at the k pointk；
Step 5, calculating the alpha according to the step 4kCalculating the mean value thereof
Figure BDA0001531968030000021
Step 6, mixing alphakComparing with alpha' and selecting subsequent processing steps according to different results;
step 7, according to the result of step 6, determining h for the point with the ice-coating cross section approximate to ellipsekAnd lkThe distribution of the four key points of the ice-coated conductor cross section is analyzed (as shown in figure 3), and the ice-coated clear area S of the cross section of the ice-coated conductor under the condition is further obtainedi；
Step 8, according to the result of the step 6, calculating the elliptical area of the point where the ice-coated cross section can not be simply approximated to an ellipse and the area of a closed area enclosed by the elliptical curve and the Gaussian curve tangent to the elliptical curve, thereby calculating the ice-coated clear area S of the cross section of the ice-coated wire under the conditioni；
Step 9, calculating an ellipse in step 7 or step 8Icing clear area S of the cross sectioniAnd then, the weight of the ice coated on the whole section of the wire can be obtained through integral operation.
The present invention is also characterized in that,
the step 1 specifically comprises the following steps: specifically, when image acquisition is carried out, the cameras are calibrated by adjusting the installation positions of the cameras for multiple times, the contours of the power transmission conductors acquired by the two cameras are determined to be consistent, so that the diameters of the conductors which are not covered with ice and are consistent in the front and the right above are obtained, and the cross section area of the original conductor which is not covered with ice is pi d2And the volume of the wire itself within a fixed length.
The step 3 is specifically that an ice coating edge profile of the ice coating conductor on a horizontal plane can be obtained through an image shot by a camera right above the conductor, n points are selected at equal intervals on the edge profile, and the width l of the cross section of the ice coating conductor at the position corresponding to any point k can be obtainedkWherein, (k ═ 0,1,2.., n); the ice coating edge profile of the ice coating conductor on the vertical plane can be obtained through the image shot by the camera right in front of the conductor, and the height of the cross section of the ice coating conductor corresponding to n positions is further obtained and is defined as the thickness hk(k＝0,1,2...,n)。
The specific calculation formula of the step 4 is as follows: alpha is alphak＝hk/lkWherein, (k ═ 0,1,2.., n); alpha is alphakIs the ratio of the long axis to the short axis of the cross section of the ice-coated wire at the k point.
In said step 6, αkThe result of the comparison with α' is divided into two cases, if αkAlpha' or less, the shape of the cross section of the ice-coated wire at the position of k point can be fitted into a shape which is respectively expressed by hkAnd lkAn ellipse with a major and minor axis; in this case, the process goes to step 7 to calculate the icing clear area S in this casei(ii) a If α isk>And alpha' indicating that the cross section shape at the k point can not be directly fitted into an ellipse, turning to step 8, and fitting the cross section shape of the ice-coated wire by combining an elliptic curve and a Gaussian curve so as to calculate the ice-coated net area.
The solving process of the representative position distribution and area of the four points in the step 7 is as follows:
and 7.1, setting two key points for determining the ice coating diameter l at a certain point on the wire as two points O and Q in the cross section, and setting two key points for determining the ice coating thickness h as two points P and R in the cross section. Wherein O, Q two points are distributed at the position of the long axis of the cross section, P, R two points are distributed at the position of the short axis of the cross section; the 4 key points have four combined distributions on the cross section, and correspondingly determine four typical icing cross section shape models;
and 7.2, in the first case, the position of the O point is lower than that of the Q point, and the P point is on the left side of the R point. If the vertical distance from the point O to the point P is a, the vertical distance from the point R to the point O is b, the vertical distance from the point Q to the point R is c, the distance from the point P to the point Q is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000041
And 7.3, in the second case, the position of the point O is higher than that of the point Q, and the point P is positioned on the right side of the point R. If the vertical distance from the point O to the point R is a, the vertical distance from the point R to the point Q is b, the vertical distance from the point Q to the point P is c, the vertical distance from the point P to the point O is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000042
In the third case, point O is higher than point Q and point P is to the left of point R. If the vertical distance from the point O to the point P is a, the vertical distance from the point R to the point Q is b, the vertical distance from the point Q to the point R is c, the vertical distance from the point P to the point O is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000043
Step 7.5, in the fourth case, point O is lower than point Q, and point P is to the right of point R. If the vertical distance from the point O to the point R is a, the vertical distance from the point R to the point O is b, and the point Q to the point PThe vertical distance is c, the vertical distance from the point P to the point Q is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000051
Step 7.6, x and y in the above four cases represent the moving distances of the two points with the maximum thickness and the two points with the maximum diameter of the ice-coated shape, respectively, and y is 0 when P, R is on a straight line, 0 when O, Q is on a straight line, 0 when P, R is collinear, and 0 when O, Q is collinear. The three cases belong to special cases, and the total cross section area of the ice-coated wire is a standard elliptical area
Figure BDA0001531968030000052
Total area of iced conductor cross-section in four cases of step 7.7, step 7.2 to step 7.5
Figure BDA0001531968030000053
The cross section icing shapes of different position points in the same period of the same wire are different, so that the probability of occurrence of four conditions is random, and the areas can be mutually offset; therefore, the cross section of the iced conductor in the step 7 can be equivalent to an elliptical point, and the ice coating clear area of the cross section at the point is
Figure BDA0001531968030000054
The specific steps of the step 8 are as follows,
step 8.1 for alphak>A point of α' at which the iced conductor cross-sectional shape is a combination of an ellipse and a Gaussian curve, wherein the minor axis of the elliptical portion is lkThe major axis iskα', then the area of the elliptical portion is
Figure BDA0001531968030000055
The ellipse equation can be expressed as:
Figure BDA0001531968030000056
step 8.2, setting the expression of the Gaussian function tangent to the ellipse in step 8.1 as
Figure BDA0001531968030000057
Wherein A, B and c are constant coefficients of Gaussian function, and function curve passing point
Figure BDA0001531968030000058
And
Figure BDA0001531968030000059
the two points are substituted into a Gaussian function expression to obtain,
Figure BDA00015319680300000510
Figure BDA0001531968030000061
because the ellipse is tangent to the Gaussian function curve, the ellipse curve and the Gaussian curve have two intersection points, namely an equation set, according to the shape characteristics of the ellipse and the Gaussian curve
Figure BDA0001531968030000062
Only two solutions are available, and the only solution of | c | is solved, so that a Gaussian function curve tangent to the ellipse can be obtained; the gaussian function is expressed as follows:
Figure BDA0001531968030000063
and 8.4, setting two tangent points of the Gaussian function (3) and the elliptic curve as follows: m (-x)0,y0) And N (x)0,y0)。
The expression of the arc MN on the ellipse is as follows:
Figure BDA0001531968030000064
the area S of a closed area formed by a Gaussian curve and an arc MN is known by an elliptic equation and a Gaussian functioncComprises the following steps:
Figure BDA0001531968030000065
the total area S of the cross section of the iced conductor in this case is then:
St＝Se+Sc (6)
the icing clear area is:
Figure BDA0001531968030000066
the step 9 specifically comprises: the icing clear area S of the elliptical cross section is calculated in step 7 or step 8iThen, the fixed length [ a, b ] can be obtained by further integral operation]The volume V of ice coated on the inter-iced conductoriLet rho be the density of ice coating on the conductor and m be the weight of ice coating on the whole conductoriComprises the following steps: m isi＝ρVi。
Compared with the existing force sensor monitoring method and capacitance sensor monitoring method, the method for identifying the icing shape of the cross section of the power transmission conductor based on the ice shape modeling has the advantages that (1) two cameras are adopted to collect images of the icing conductor from the right front and the right upper part respectively, the irregular icing shape of the power transmission conductor is identified through an image processing technology and mathematical modeling, the irregular icing of the conductor can be identified more intuitively and accurately, and an effective mode is provided for the state maintenance of the modern power transmission conductor;
(2) the method for identifying the icing shape of the cross section of the power transmission conductor based on the ice-shaped modeling is characterized in that visible light images of the conductor are collected through cameras at two specific positions, the edges of the conductor in the images at the two positions are respectively extracted, the icing shape of the cross section at different positions on the conductor can be intuitively and accurately simulated by combining mathematical modeling, the icing clear area of the cross section of the conductor and the icing volume and the icing weight within a fixed length can be further obtained, and an intuitive, effective and feasible new method is provided for identifying and detecting the irregular icing shape of the icing power transmission conductor.
Drawings
FIG. 1 is a flow chart of the method of the present invention;
FIG. 2(a) is a schematic diagram showing a first positional relationship of four points in step 7 of the method of the present invention;
FIG. 2(b) is a schematic diagram showing a second positional relationship of four points in step 7 of the method of the present invention;
FIG. 2(c) is a schematic view showing a third positional relationship of four points in step 7 in the method of the present invention;
FIG. 2(d) is a schematic diagram showing a fourth positional relationship of four points in step 7 of the method of the present invention;
fig. 3 is a schematic view of the cross-sectional shape of the iced conductor in the method of the present invention as a combination of elliptical and gaussian curves.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
A method for identifying an icing shape of a cross section of a power transmission conductor based on ice shape modeling is implemented according to the following steps as shown in figure 1:
step 1, installing cameras according to the positions of a wire and an iron tower, wherein one camera is installed above the wire, the other camera is installed in a position parallel to the wire, calibrating the position of the camera, and acquiring images of the wire when ice is not coated;
specifically, when image acquisition is carried out, the cameras are calibrated by adjusting the installation positions of the cameras for multiple times, the contours of the power transmission conductors acquired by the two cameras are determined to be consistent, so that the diameters of the conductors which are not covered with ice and are consistent in the front and the right above are obtained, and the cross section area of the original conductor which is not covered with ice is pi d2And the volume of the wire itself within a fixed length.
And 2, acquiring images of the conductor coated with ice by using the two cameras arranged in the step 1, and acquiring images of the conductor coated with ice at positions right above and right in front of the conductor coated with ice.
Step 3, respectively carrying out image preprocessing and image segmentation on the images of the ice-coated wire acquired by the two cameras in the step 2, and further extracting the edge contour of the ice-coated wire; and drawing the outer contour shape of the cross section of the lead, wherein the specific method comprises the following steps:
the ice-coated edge contour of the ice-coated wire on the horizontal plane can be obtained through the image shot by the camera right above the wire, n points are selected on the edge contour at equal intervals, and the width l of the cross section of the ice-coated wire at the position corresponding to any point k can be obtainedkWherein, (k ═ 0,1,2.., n);
the ice coating edge profile of the ice coating conductor on the vertical plane can be obtained through the image shot by the camera right in front of the conductor, and the height of the cross section of the ice coating conductor corresponding to n positions is further obtained and is defined as the thickness hk(k＝0,1,2...,n)；
Step 4, obtaining l according to the step 3kAnd hkCalculating the ratio alpha of the long axis to the short axis of the cross section of the ice-coated wire at the k pointk，
The specific calculation formula is as follows: alpha is alphak＝hk/lkWherein, (k ═ 0,1,2.., n);
αkis the ratio of the long axis to the short axis of the cross section of the ice-coated wire at the k point.
Step 5, calculating the alpha according to the step 4kCalculating the mean value thereof
Figure BDA0001531968030000091
Step 6, mixing alphakComparing with alpha' and selecting subsequent processing steps according to different results;
αkthe result of the comparison with α' is divided into two cases, if αkAlpha' or less, the shape of the cross section of the ice-coated wire at the position of k point can be fitted into a shape which is respectively expressed by hkAnd lkAn ellipse with a major and minor axis; in this case, the process goes to step 7 to calculate the icing clear area S in this casei；
If α isk>And alpha' indicating that the cross section shape at the k point can not be directly fitted into an ellipse, turning to step 8, and fitting the cross section shape of the ice-coated wire by combining an elliptic curve and a Gaussian curve so as to calculate the ice-coated net area.
Step 7, according to the result of the step 6, determining h for the point of which the ice-coating cross section is approximate to an ellipsekAnd lkThe distribution of the four key points of the ice-coated conductor cross section is analyzed (as shown in figure 3), and the ice-coated clear area S of the cross section of the ice-coated conductor under the condition is further obtainedi(ii) a The four key points refer to the outermost 4 points of the cross-sectional profile shown on the figure of the ice-coated wire; the four points are typically solved for several position distributions and areas as follows:
and 7.1, setting two key points for determining the ice coating diameter l at a certain point on the wire as two points O and Q in the cross section, and setting two key points for determining the ice coating thickness h as two points P and R in the cross section. Wherein O, Q two points are distributed at the position of the long axis of the cross section, P, R two points are distributed at the position of the short axis of the cross section; the 4 key points have four combined distributions on the cross section, and correspondingly determine four typical ice coating cross section shape models.
In the first case of step 7.2, as shown in fig. 2(a), the O point is lower than the Q point, and the P point is on the left side of the R point. If the vertical distance from the point O to the point P is a, the vertical distance from the point R to the point O is b, the vertical distance from the point Q to the point R is c, the distance from the point P to the point Q is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000101
In the second case, step 7.3, as shown in fig. 2(b), the point O is higher than the point Q, and the point P is on the right side of the point R. If the vertical distance from the point O to the point R is a, the vertical distance from the point R to the point Q is b, the vertical distance from the point Q to the point P is c, the vertical distance from the point P to the point O is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000102
In step 7.4, in the third case, as shown in fig. 2(c), the O point is higher than the Q point, and the P point is on the left side of the R point. If the vertical distance from the point O to the point P is a, the vertical distance from the point R to the point Q is b, the vertical distance from the point Q to the point R is c, the vertical distance from the point P to the point O is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000103
Step 7.5, fourth case, as shown in fig. 2(d), point O is lower than point Q, and point P is on the right side of point R. If the vertical distance from the point O to the point R is a, the vertical distance from the point R to the point O is b, the vertical distance from the point Q to the point P is c, the vertical distance from the point P to the point Q is d, and the side length of the micro rectangle enclosed by the middle is x and y. The total cross-sectional area of the ice-coated wire can be derived
Figure BDA0001531968030000104
Step 7.6, x and y in the above four cases represent the moving distances of the two points with the maximum thickness and the two points with the maximum diameter of the ice-coated shape, respectively, and y is 0 when P, R is on a straight line, 0 when O, Q is on a straight line, 0 when P, R is collinear, and 0 when O, Q is collinear. The three cases belong to special cases, and the total cross section area of the ice-coated wire is a standard elliptical area
Figure BDA0001531968030000105
Total area of iced conductor cross-section in four cases of step 7.7, step 7.2 to step 7.5
Figure BDA0001531968030000106
The method belongs to a tiny amount, and because the ice coating shapes of the cross sections of different positions of the same lead at the same time are different, the probability of the occurrence of the models (a), (b), (c) and (d) in four cases is random, and the areas can be mutually offset. Therefore, the ice coating in step 7 is conductedThe line cross-section may be equivalent to the point of an ellipse at which the cross-sectional icing clear area is
Figure BDA0001531968030000111
Step 8, according to the result of the step 6, calculating the elliptical area of the point where the ice-coated cross section can not be simply approximated to an ellipse and the area of a closed area enclosed by the elliptical curve and the Gaussian curve tangent to the elliptical curve, thereby calculating the ice-coated clear area S of the cross section of the ice-coated wire under the conditioni；
The method comprises the following specific steps:
step 8.1 for alphak>A point of α' at which the iced conductor cross-sectional shape is a combination of an ellipse and a Gaussian curve, wherein the minor axis of the elliptical portion is lkThe major axis iskα', then the area of the elliptical portion is
Figure BDA0001531968030000112
The ellipse equation can be expressed as:
Figure BDA0001531968030000113
step 8.2, setting the expression of the Gaussian function tangent to the ellipse in step 8.1 as
Figure BDA0001531968030000114
Wherein A, B and c are constant coefficients of Gaussian function, and function curve passing point
Figure BDA0001531968030000115
And
Figure BDA0001531968030000116
the two points are substituted into a Gaussian function expression to obtain,
Figure BDA0001531968030000117
Figure BDA0001531968030000118
because the ellipse is tangent to the Gaussian function curve, the ellipse curve and the Gaussian curve have two intersection points, namely an equation set, according to the shape characteristics of the ellipse and the Gaussian curve
Figure BDA0001531968030000119
And solving the unique solution of | c | by only two solutions to obtain the Gaussian function curve tangent to the ellipse. The gaussian function is expressed as follows:
Figure BDA0001531968030000121
and 8.4, setting two tangent points of the Gaussian function (3) and the elliptic curve as follows: m (-x)0,y0) And N (x)0,y0)。
The expression of the arc MN on the ellipse is as follows:
Figure BDA0001531968030000122
the area S of a closed area formed by a Gaussian curve and an arc MN is known by an elliptic equation and a Gaussian functioncComprises the following steps:
Figure BDA0001531968030000123
the total area S of the cross section of the iced conductor in this case is then:
St＝Se+Sc (6)
the icing clear area is:
Figure BDA0001531968030000124
step 9, calculating the icing clear area S of the elliptic cross section in step 7 or step 8iThen, the fixed length [ a, b ] can be obtained by further integral operation]The volume V of ice coated on the inter-iced conductoriLet rho be the density of ice coating on the conductor and m be the weight of ice coating on the whole conductoriComprises the following steps: m isi＝ρVi。

Claims (4)

1.一种基于冰形建模的输电导线横截面覆冰形状识别方法，其特征在于，具体按照以下步骤实施：1. a method for identifying ice-covered shape of a power transmission wire cross-section based on ice-shape modeling, is characterized in that, specifically implements according to the following steps: 步骤1，依据导线与铁塔的位置安装摄像机，一个摄像机安装在导线的上方，另一个安装在平行于导线的位置，校准摄像机位置，进行未覆冰时的导线的图像采集；Step 1, install cameras according to the position of the wire and the tower, one camera is installed above the wire, and the other is installed in a position parallel to the wire, calibrate the position of the camera, and collect the image of the wire when the ice is not covered; 所述的步骤1具体为：The step 1 is specifically: 具体在进行图像采集时，通过多次调整摄像机的安装位置来进行摄像机校准，确定两台摄像机所采集到的输电导线的轮廓一致，从而正前方和正上方的得到一致的未覆冰导线直径为d1，进而可知原始未覆冰导线的横截面面积为
Figure FDA0003231084760000011
以及固定长度内导线自身体积；Specifically, during image acquisition, the camera is calibrated by adjusting the installation position of the camera several times to ensure that the outlines of the transmission wires collected by the two cameras are consistent, so that the unice-coated wires directly in front and directly above have a consistent diameter of d. 1 , and then it can be known that the cross-sectional area of the original unice-coated wire is
Figure FDA0003231084760000011
And the volume of the wire itself within a fixed length; 步骤2，利用步骤1中设置的两台摄像机对已经覆冰的导线图像进行采集，进行正上方和正前方位置的覆冰导线进行图像采集；Step 2, use the two cameras set in step 1 to collect the image of the ice-coated wire, and perform image capture of the ice-coated wire directly above and directly in front; 步骤3，对步骤2中两台摄像机采集到的覆冰导线图像分别进行图像预处理、图像分割，进而提取覆冰导线的边缘轮廓；并绘制出导线横截面外轮廓形状，所述的步骤3具体为，Step 3: Perform image preprocessing and image segmentation on the images of the ice-coated wire collected by the two cameras in step 2, respectively, and then extract the edge contour of the ice-coated wire; and draw the outer contour shape of the wire cross-section. Specifically, 通过导线正上方摄像机拍摄的图像，可获得覆冰导线在水平平面的覆冰边缘轮廓，在该边缘轮廓上等间隔地选取n个点，即可得到其中任意的点k对应位置的覆冰导线横截面的宽度lk，其中，k＝0,1,2...,n；Through the image captured by the camera directly above the wire, the ice-coated edge contour of the ice-coated wire in the horizontal plane can be obtained. By selecting n points at equal intervals on the edge contour, the ice-coated wire at the corresponding position of any point k can be obtained. the width lk of the cross section, where k =0,1,2...,n; 通过导线正前方摄像机拍摄的图像，可获得覆冰导线在垂直平面的覆冰边缘轮廓，进而得到对应n个位置点处覆冰导线横截面的高度，定义为厚度hk，k＝0,1,2...,n；Through the image captured by the camera in front of the conductor, the contour of the ice-covered edge of the ice-covered conductor in the vertical plane can be obtained, and then the height of the cross-section of the ice-covered conductor at the corresponding n position points can be obtained, which is defined as the thickness h k , k=0,1 ,2...,n; 步骤4，根据步骤3得到的lk和hk，计算k点处覆冰导线横截面的长短轴之比αk；Step 4, according to l k and h k obtained in step 3, calculate the ratio α k of the long and short axes of the cross section of the ice-coated wire at point k ; 所述的步骤4的具体计算公式为：αk＝hk/lk，其中，k＝0,1,2...,n；αk为k点处覆冰导线横截面的长短轴之比；The specific calculation formula of the step 4 is: α k =h k /l k , where k =0,1,2...,n; Compare; 步骤5，根据步骤4计算得到的αk，求其均值
Figure FDA0003231084760000021
Step 5, according to the α k calculated in step 4, find its mean
Figure FDA0003231084760000021
 步骤6、将αk与α′进行比较，根据不同的结果选择后续处理步骤；Step 6. Compare α k with α′, and select subsequent processing steps according to different results; 步骤7，根据步骤6的结果，对覆冰横截面近似为椭圆的点，对该点处决定hk和lk的四个关键点在覆冰导线横截面的位置分布进行分析，进而求出该情况下覆冰导线的横截面覆冰净面积Si；Step 7: According to the result of Step 6, for the point where the ice-coated cross-section is approximately an ellipse, analyze the position distribution of the four key points that determine h k and l k on the ice-coated wire cross-section, and then obtain In this case, the ice-covered net area Si of the cross-section of the ice-covered wire ; 所述的步骤7中的四个点的代表性的几种位置分布及面积求解过程如下：Several representative position distributions and area solving processes of the four points in the step 7 are as follows: 步骤7.1、将决定导线上某点处覆冰直径l的两个关键点设为横截面中的O和Q两点，决定覆冰厚度h的两个关键点为横截面中的P和R两个点；其中，O、Q两点分布在横截面的长轴的位置，P、R两点分布在横截面的短轴的位置；这4个关键点在横截面上有四种组合分布，对应决定了四种典型的覆冰横截面形状模型；Step 7.1. Set the two key points that determine the ice coating diameter l at a certain point on the wire as the two points O and Q in the cross section, and the two key points that determine the ice coating thickness h are the two key points P and R in the cross section. Among them, two points O and Q are distributed at the position of the long axis of the cross section, and two points P and R are distributed at the position of the short axis of the cross section; these four key points are distributed in four combinations on the cross section, Correspondingly, four typical ice-covered cross-sectional shape models were determined; 步骤7.2，第一种情况，O点位置较Q点位置低，且P点在R点左侧；若设O点到P点垂直距离为a，R点到O点垂直距离为b，Q点到R点垂直距离为c，P点到Q点距离为d，中间围成的微小矩形边长为x，y；则覆冰导线横截面总面积经推导可得
Figure FDA0003231084760000022
Step 7.2, in the first case, the position of point O is lower than that of point Q, and point P is on the left side of point R; if the vertical distance from point O to point P is a, the vertical distance from point R to point O is b, and point Q The vertical distance to point R is c, the distance from point P to point Q is d, and the side lengths of the tiny rectangle enclosed in the middle are x, y; then the total cross-sectional area of the ice-coated conductor can be obtained by derivation
Figure FDA0003231084760000022
 步骤7.3、第二种情况，O点较Q点位置高，且P点在R点右侧；若设O点到R点垂直距离为a，R点到Q点垂直距离为b，Q点到P点垂直距离为c，P点到O点垂直距离为d，中间围成的微小矩形边长为x，y；则覆冰导线横截面总面积经推导可得
Figure FDA0003231084760000031
Step 7.3. In the second case, point O is higher than point Q, and point P is on the right side of point R; if the vertical distance from point O to point R is a, the vertical distance from point R to point Q is b, and point Q to The vertical distance from point P is c, the vertical distance from point P to point O is d, and the side lengths of the tiny rectangle enclosed in the middle are x, y; then the total cross-sectional area of the ice-coated wire can be derived by derivation
Figure FDA0003231084760000031
 步骤7.4，第三种情况，O点较Q点位置高，且P点在R点左侧；若设O点到P点垂直距离为a，R点到Q点垂直距离为b，Q点到R点垂直距离为c，P点到O点垂直距离为d，中间围成的微小矩形边长为x，y；则覆冰导线横截面总面积经推导可得
Figure FDA0003231084760000032
Step 7.4, the third case, point O is higher than point Q, and point P is on the left side of point R; if the vertical distance from point O to point P is a, the vertical distance from point R to point Q is b, and point Q to The vertical distance from point R is c, the vertical distance from point P to point O is d, and the side lengths of the tiny rectangle enclosed in the middle are x, y; then the total cross-sectional area of the ice-coated conductor can be obtained by derivation
Figure FDA0003231084760000032
 步骤7.5，第四种情况，O点较Q点位置低，且P点在R点右侧；若设O点到R点垂直距离为a，R点到O点垂直距离为b，Q点到P点垂直距离为c，P点到Q点垂直距离为d，中间围成的微小矩形边长为x，y；则覆冰导线横截面总面积经推导可得
Figure FDA0003231084760000033
Step 7.5, in the fourth case, point O is lower than point Q, and point P is on the right side of point R; if the vertical distance from point O to point R is a, the vertical distance from point R to point O is b, and point Q to The vertical distance from point P is c, the vertical distance from point P to point Q is d, and the side lengths of the tiny rectangle enclosed in the middle are x and y;
Figure FDA0003231084760000033
 步骤7.6、以上四种情况中的x和y分别表示覆冰形状厚度最大两点及直径最大的两点的移动距离，当P、R在一条直线上时y＝0，当O、Q在一条直线上时x＝0，当P、R共线，且O、Q共线时，x＝0，y＝0；这三种情况属于特殊情况，此时覆冰导线横截面总面积为标准的椭圆面积
Figure FDA0003231084760000034
Step 7.6. In the above four cases, x and y represent the moving distance of the two points with the largest thickness and the largest diameter of the ice-covered shape, respectively. When P and R are on a straight line, y=0, and when O and Q are on a straight line. When on a straight line, x=0, when P, R are collinear, and O, Q are collinear, x=0, y=0; these three cases are special cases, and the total cross-sectional area of the ice-coated wire is the standard Ellipse area
Figure FDA0003231084760000034
 步骤7.7、步骤7.2到步骤7.5的四种情况中的覆冰导线横截面总面积中
Figure FDA0003231084760000035
属于微小量，且由于同根导线相同时期不同位置点的横截面覆冰形状存在差异，四种情况出现的几率随机，面积可相互抵消；因此，对步骤7中的覆冰导线横截面可以等效为椭圆的点，该点处的横截面覆冰净面积为
Figure FDA0003231084760000036
Of the total cross-sectional area of the ice-coated wire in the four cases of Step 7.7, Step 7.2 to Step 7.5
Figure FDA0003231084760000035
It belongs to a small amount, and because the cross-sectional ice-covered shape of the same wire at different locations in the same period is different, the probability of occurrence of the four cases is random, and the areas can cancel each other; therefore, the cross-section of the ice-covered wire in step 7 can be equivalent is the point of the ellipse, and the net ice-covered area of the cross-section at this point is
Figure FDA0003231084760000036
 步骤8，根据步骤6的结果，对覆冰横截面不能简单近似为椭圆的点，计算出该点处椭圆面积，以及椭圆曲线和与其相切的高斯曲线围成的封闭区域的面积，从而即可计算出该情况下覆冰导线的横截面覆冰净面积Si；Step 8: According to the result of Step 6, for the point where the ice cross section cannot be simply approximated as an ellipse, calculate the ellipse area at the point and the area of the closed area enclosed by the elliptic curve and the Gaussian curve tangent to it, so that In this case, the ice-covered net area Si of the cross-section of the ice-covered wire can be calculated ; 步骤9，在步骤7或步骤8计算出椭圆横截面的覆冰净面积Si后，可进一步通过积分运算，求得整段导线覆冰的重量。Step 9, after calculating the net ice-covered area S i of the elliptical cross-section in step 7 or step 8, the ice-covered weight of the entire wire can be obtained by further integral operation. 2.根据权利要求1所述的基于冰形建模的输电导线横截面覆冰形状识别方法，其特征在于，所述的步骤6中，αk与α′的比较结果分为两种情况，如果αk≤α′，则k点位置的覆冰导线横截面的形状可以拟合为一个分别以hk和lk为长短轴的椭圆；这种情况下，则转至步骤7计算此种情况下的覆冰净面积Si；如果αk＞α′，说明此时k点处的截面形状无法直接拟合为椭圆，则转至步骤8，采用椭圆曲线与高斯曲线相结合拟合覆冰导线截面形状，从而计算覆冰净面积。2. The method for recognizing the shape of ice-covered cross-sections of transmission wires based on ice-shape modeling according to claim 1, wherein in the step 6, the comparison results of α k and α′ are divided into two cases, If α k ≤α′, the shape of the ice-coated wire cross-section at point k can be fitted to an ellipse with hk and lk as the major and minor axes respectively; in this case, go to step 7 to calculate the If α k >α′, it means that the cross-sectional shape at point k cannot be directly fitted to an ellipse, then go to step 8 and use a combination of elliptic curve and Gaussian curve to fit the icing Ice wire cross-sectional shape, so as to calculate the net ice area. 3.根据权利要求1所述的基于冰形建模的输电导线横截面覆冰形状识别方法，其特征在于，所述的步骤8的具体步骤为，3. The method for recognizing the shape of ice-covered cross-section of a power transmission wire based on ice-shape modeling according to claim 1, wherein the specific steps of step 8 are: 步骤8.1、对于αk＞α′的点，该点处覆冰导线横截面形状为椭圆和高斯曲线的组合，其中椭圆部分的短轴为lk，长轴为lkα′，则椭圆部分的面积为
Figure FDA0003231084760000041
Step 8.1. For the point where α k >α', the cross-sectional shape of the ice-coated wire at this point is a combination of an ellipse and a Gaussian curve, where the short axis of the ellipse is l k and the long axis is l k α', then the ellipse part The area of is
Figure FDA0003231084760000041
 椭圆方程可表示为：The ellipse equation can be expressed as:
Figure FDA0003231084760000042
Figure FDA0003231084760000042
 步骤8.2、设与步骤8.1中的椭圆相切的高斯函数表达式为
Figure FDA0003231084760000043
其中A、B和c为高斯函数的常系数，函数曲线过点
Figure FDA0003231084760000044
及
Figure FDA0003231084760000045
将两点代入高斯函数表达式中可求得，
Figure FDA0003231084760000046
Figure FDA0003231084760000047
Step 8.2. Let the expression of the Gaussian function tangent to the ellipse in step 8.1 be
Figure FDA0003231084760000043
Among them, A, B and c are constant coefficients of the Gaussian function, and the function curve passes through the points
Figure FDA0003231084760000044
and
Figure FDA0003231084760000045
Substituting two points into the Gaussian function expression can be obtained,
Figure FDA0003231084760000046
Figure FDA0003231084760000047
 因椭圆与高斯函数曲线相切，根据椭圆与高斯曲线的形状特征，椭圆曲线与高斯曲线有且仅有两个交点，即方程组Because the ellipse and the Gaussian function curve are tangent, according to the shape characteristics of the ellipse and the Gaussian curve, the elliptic curve and the Gaussian curve have one and only two intersection points, namely the equation system.
Figure FDA0003231084760000051
Figure FDA0003231084760000051
 有且仅有两个解，求取|c|的唯一解，即可获取与椭圆相切的高斯函数曲线；高斯函数表达式如下：There are only two solutions, and by finding the unique solution of |c|, the Gaussian function curve tangent to the ellipse can be obtained; the Gaussian function is expressed as follows:
Figure FDA0003231084760000052
Figure FDA0003231084760000052
 步骤8.4、设高斯函数(3)与椭圆曲线的两切点为：M(-x0,y0)和N(x0,y0)；Step 8.4. Set the two tangent points between the Gaussian function (3) and the elliptic curve: M(-x 0 , y 0 ) and N(x 0 , y 0 ); 椭圆上弧线MN的表达式为：The expression for the arc MN on the ellipse is:
Figure FDA0003231084760000053
Figure FDA0003231084760000053
 椭圆方程及高斯函数已知，高斯曲线与弧线MN所形成的封闭区域的面积Sc为：The elliptic equation and the Gaussian function are known, and the area S c of the closed region formed by the Gaussian curve and the arc MN is:
Figure FDA0003231084760000054
Figure FDA0003231084760000054
 则这种情况下覆冰导线横截面的总面积S为：In this case, the total area S of the cross section of the ice-coated wire is: St＝Se+Sc (6)S t =S e +S c (6) 覆冰净面积为：The net icing area is:
Figure FDA0003231084760000055
Figure FDA0003231084760000055
 4.根据权利要求1所述的基于冰形建模的输电导线横截面覆冰形状识别方法，其特征在于，所述的步骤9具体为：在步骤7或步骤8计算出椭圆横截面的覆冰净面积Si后，可进一步通过积分运算，求出固定长度[a,b]之间覆冰导线上的覆冰体积Vi，设导线上覆冰的密度为ρ，整段导线覆冰的重量mi为：mi＝ρVi。4. The method for recognizing the shape of ice-covered cross-section of a transmission wire based on ice-shape modeling according to claim 1, wherein the step 9 is specifically: in step 7 or step 8, calculating the cover of the ellipse cross-section. After the net ice area S i , the ice-covered volume V i on the ice-covered wire between the fixed lengths [a, b] can be obtained by further integral operation, and the ice-covered density on the wire is set as ρ, and the ice-covered wire of the entire length of the wire is The weight m i of is: m i =ρV i .
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CN109325956A (en) * 2018-08-15 2019-02-12 国网河南省电力公司电力科学研究院 An image processing-based feature extraction method for ice-coated cross-sections of power transmission lines
CN110146008B (en) * 2019-05-16 2021-02-12 西安工程大学 Method for monitoring icing parameters and states based on interdigital capacitive sensor
CN111637839A (en) * 2020-06-01 2020-09-08 中国南方电网有限责任公司超高压输电公司昆明局 Digital ice coating thickness measuring device and measuring method
CN112508913B (en) * 2020-12-10 2024-07-05 国网江西省电力有限公司电力科学研究院 Cable section edge detection method based on image detection
CN114359763B (en) * 2022-01-11 2025-06-06 北京国网富达科技发展有限责任公司 A front-end monitoring method and system for ice dancing on overhead power transmission lines
CN115330787B (en) * 2022-10-13 2023-01-24 国网山西省电力公司电力科学研究院 Photovoltaic module icing area detection method based on image recognition

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101793501A (en) * 2010-04-14 2010-08-04 华中科技大学 Transmission line ice coating status detection method based on image
CN102252623A (en) * 2011-06-24 2011-11-23 西安工程大学 Measurement method for lead/ground wire icing thickness of transmission line based on video variation analysis
CN104809727A (en) * 2015-04-24 2015-07-29 西安工程大学 Automatic transmission conductor icing shape identification method
CN106407994A (en) * 2016-09-29 2017-02-15 武汉大学 Wire icing thickness image recognition method based on Hough transform and function fitting

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103101626B (en) * 2012-12-04 2015-09-02 中国商用飞机有限责任公司 Icing detector

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101793501A (en) * 2010-04-14 2010-08-04 华中科技大学 Transmission line ice coating status detection method based on image
CN102252623A (en) * 2011-06-24 2011-11-23 西安工程大学 Measurement method for lead/ground wire icing thickness of transmission line based on video variation analysis
CN104809727A (en) * 2015-04-24 2015-07-29 西安工程大学 Automatic transmission conductor icing shape identification method
CN106407994A (en) * 2016-09-29 2017-02-15 武汉大学 Wire icing thickness image recognition method based on Hough transform and function fitting

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
Online Technology for Measuring Icing Shape on Conductor Based on Vision and Force Sensors;Xinbo Huang et al;《LFFF TRANSACTLONS ON LNSTRLJMFNTATLON ANO MFASLJRFMFNT》;20170926;第3180-3189页 *
复杂环境下覆冰绝缘子识别检测技术;黄新波等;《高电压技术》;20170331;第43卷(第3期);第891-899页 *
自然覆冰条件下的输电线路覆冰形状特征;范松海;《四川电力技术》;20140831;第37卷(第4期);第14-75页 *
输电线路绝缘子覆冰厚度图像识别算法;张烨等;《电力系统自动化》;20161110;第40卷(第21期);第195-202页 *

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